${}^8\mathrm{B}+{}^{27}\mathrm{Al}$ scattering at low energies

We present ${}^8\mathrm{B}+{}^{27}\mathrm{Al}$ elastic scattering angular distributions for the proton-halo nucleus ${}^8\mathrm{B}$ at two energies above the Coulomb barrier, namely $E_{\mathrm{lab}}=15.3$ and 21.7 MeV. The experiments were performed in the Radioactive Ion Beams in Brasil facility (RIBRAS) in São Paulo, and in the TwinSol facility at the University of Notre Dame, USA. The angular distributions were measured in the angular range of 15–80 degrees. Optical model and continuum discretized coupled channels calculations were performed, and the total reaction cross sections were derived. A comparison of the ${}^8\mathrm{B}+{}^{27}\mathrm{Al}$ total reaction cross sections with similar systems including exotic, weakly bound, and tightly bound projectiles impinging on the same target is presented.

Figure 1

Bidimensional $\mathrm{\Delta }E\text{−}E$ spectrum for ${}^8\mathrm{B}+{}^{27}\mathrm{Al}$ corresponding to an average energy $E_0=18.0\text{MeV}$ and ${\theta }_{\mathrm{lab}}={20}^{\circ }$.

Figure 2

One-dimensional spectrum for the secondary beam scattered on ${}^{27}\mathrm{Al}$ obtained at the RIBRAS facility. The ${}^8\mathrm{B}$ beam incident energy is $E_0=18.0$ MeV.

Figure 3

The ${}^8\mathrm{B}+{}^{27}\mathrm{Al}$ elastic scattering angular distributions. The solid circles represent the experimental data, while the dotted red and the dashed curves are the results of calculations using the SPP and WS potential, respectively. The CDCC results are represented by the solid blue curve and the dot-dashed curves represent results where all the couplings are switched off (one channel).

Figure 4

Reduced reaction cross sections for several projectiles on ${}^{27}\mathrm{Al}$ target. The dashed curves are a guide for the eyes.

Figure 5

Comparison of reduced total reaction cross section for the same systems shown in Fig. 4 for the case of the reduction of ${\sigma }^{\exp }$ by ${\sigma }^{CC}$. See text for details.